A DCT MATRIX DECOMPOSING DEVICE AND A DCT DEVICE USING THE SAME

Abstract

The present invention relates to a DCT matrix decomposing device for decomposing a one-dimensional DCT matrix,being adapted to perform a DCT operation only through addition and subtraction operations,the arrangement being such that an N x N one-dimensional DCT matrix is caused to be decomposed into a pluralityof sub-matrices and zero matrix by using the symmetry of a cosine function,each of the sub-matrices is caused to be factorized,to make it possible to express each of the sub-matrices by the product of an intermediate matrix and one or more first matrices the elements of which are 1, -1 or 0 in value,wherein the intermediate matrix contains a cosine coefficient as a matrix element;and a factorization process of each of the intermediate matrices is caused to be repeated a necessary number of times to make it possible to express each of the intermediate matrices by the product of second matrices the elements of which are 1,-1 or 0 in value.A DCT device for processing an input signal obtained using the said DCT matrix decomposing device is also disclosed.